Other Routes of Exposure
by SolarRose29
Summary: Tony, Steve, and Clint must find a way out of the tunnel before the waters rise and kill them all.


"Check him again."

Tony rolled his eyes, crossing his arms as Steve shifted the burden in his arms. "He's the exact same as the last few hundred times you've asked me to."

"Would you just do it?" Steve snapped. Guilt immediately softened his expression. "Please."

The gentle glow of the arc reactor illuminated the tunnel walls as Tony came closer, boots sloshing through the water where it lapped against his ankles. While Steve held Clint steady, Tony performed a quick scan.

"What's the diagnosis, FRIDAY?"

"Vitals are holding steady within acceptable parameters. The fractured tibia is unchanged."

Tony nodded to himself. "And the helmet?"

"The filtration systems are operating at satisfactory levels."

"We're all good here, Cap," Tony reported. He frowned at the sheen of sweat over Steve's face. The way it reflected the light of his arc reactor made Steve look wan and ill. "I wish you'd let me give you one too."

"One what?" Steve grunted, hefting the unconscious archer more securely against his chest.

Tony tapped a knuckle to the nanotech covering Clint's head. "One of these."

Steve sighed wearily as he turned and restarted their trek down the tunnel. "We've already discussed this."

"No, that was not a discussion. That was you being a scientifically-ignorant martyr." Tony waited a moment before following. Maybe it was a childish and futile gesture of rebellion but it was the only way he could think of to express his disapproval.

"Look, if I needed one, I would accept it. Gladly," Steve tossed over his shoulder. "But I don't, so it's not worth it to compromise your suit further."

Tony frowned when Steve faced forwards once more. "I think you're underestimating my tech."

Steve's voice bounced back to him from around the slight bend up ahead. "You're the one who told me your suit was damaged in the first place."

Water splashed lightly into the curved walls as Tony hurried to catch up. "Okay, yes, but you try taking a direct hit to your power source and see how uncompromised you are. And you're trying to distract me! The point is, I don't think it's smart for you to be walking around, practically naked, when this tunnel is flooded with who knows what kinds of chemicals."

"I'm fully clothed," Steve reminded.

"It's a figure of speech." Tony threw his hands up. "I meant that you're leaving yourself vulnerable when you could be smart and just take the damn helmet."

"You want to be smart about this? Okay. Let's think. Who here has a serum that's basically built-in armor?"

Tony gave a frustrated huff. "You're not listening to me. Here, let me explain it. Like I'm talking to a five year old." He fixed Steve with an antagonistic glare. Unfortunately, the expression was hidden beneath his helmet and Steve never saw it. "The serum. Your 'built-in armor'. What's it made out of?"

Over Clint's head, where it lolled on Steve's shoulder, Steve cut his eyes sideways to Tony. "I don't know. No one really does. The formula was lost with Dr. Erskine."

"No, I know. I mean, broadly speaking. What's it made of?" When Steve kept walking with a perplexed look on his face instead of answering, Tony had to answer for him. "Chemicals, genius. It's made up of some mysterious collection of chemicals. But do you know what happens when you mix chemicals that aren't supposed to be mixed?" The confusion never left Steve's face, forcing Tony to carry the conversation by himself. "You get a chemical reaction. You get displacement. You get decomposition. Combustion. Does any of that sound like something you want to happen to you? If I get a vote, I'm definitely against combustion."

"Relax, Stark. I'm not going to explode."

"Sure," Tony snorted. "You say that now. But just wait until-"

Steve spun around on his heel. "You're not helping! Can you shut up for just two minutes? Gawd, we've been down here who knows how long and you've been talking the entire time."

Tony stopped short. "Duh. Have you met me?"

"Well, I'd like you to stop. Please. Just for a few minutes. Let me get some peace and quiet for just a few minutes so I can think of a way out of here."

"I thought we were just going to follow the tunnel," Tony said. "That seems like the most logical thing to do in this situation. Especially since, you know, you won't let me use my suit to blast us out of here."

Steve took a deep breath, coughing a little on the exhale. "Look, you said so yourself. We don't want any chemical reactions down here. I may not know much about science but I know that most gases are flammable." He gestured to the fumes thick in the air around them, swirling languidly in the glow of Tony's reactor. "So blasting is definitely out of the question, even if your suit had enough power."

"What is with you and hating on my suit? Take it easy, will you? How would you feel if someone kept insulting you for no good reason?"

"Tony!" Steve's shout echoed. "I need you to stop talking."

"Geez, touchy," Tony muttered under his breath.

"Please." Steve blinked repeatedly and for a moment, Tony was horrified to think he was going to cry. But when Steve shook his head and blinked some more, he realized the red rimmed eyes were due to external irritation rather than gathering tears.

Despite his reputation as a cold-hearted narcissist, Tony wasn't so insensitive as to ignore the same plea twice. So he shut his mouth and sloughed after Steve. The vapors of whatever gas had been released were ghostly spectators to their progress, twisting and shifting in the limited light available. Something further off was dripping. A leak somewhere in the concrete, allowing concentrated amounts of unknown chemical liquid to spill further into the tunnel. The echoing drip was maddening. Tony tried not to notice. But of course the harder he tried to ignore it, the louder it seemed to grow. He pushed it out of his mind, focusing instead on the wet sound of Steve's footsteps. The soldier's shadow was a misshapen thing curling up the side of the tunnel toward the ceiling. Tony quickened his pace until he was even with him, eliminating the strange cast of his silhouette. It was nearly impossible to reign in the urge to comment, to narrate, to think out loud or chatter or ramble or just plain make noise to chase away the stifling silence.

Steve stumbled. It took both of them by surprise, the way his body tilted abruptly. He knocked into the dampened wall, hissing when his bare hand touched the moisture there. When he instinctively yanked his hand away, he lost his balance again, and this time he fell back, jarring Clint's injured leg. The archer came awake with a gasp, jerking in Steve's grip. The pair of them crashed into the water. Clint howled in pain, hands flying to his injury.

"Whoa! Everyone alright?" Tony hovered beside them, uncertain of how to help.

Sputtering curses and gasping through the pain, Clint ignored him. Steve planted a hand against the floor, grimacing, and pushed himself upright. He quickly reached down and hauled Clint up too, holding the archer to his side when the wounded leg gave out on him.

"What happened? Where are we? What's wrong with my leg? And what the hell is this?" Clint's hand drifted up to the helmet, fingers exploring the surface.

"The mission went pear shaped as usual, you fractured your leg, and we're in some kind of underground access tunnel which is contaminated with whatever they were working on up there so-Don't!" Tony summarized in a rush, eager to stop Clint as he was reaching to remove the nanotech. "Don't take that off."

"This feels ridiculous," Clint muttered.

"Looks ridiculous too," Tony added.

"You're one to talk."

Tony lifted his hands chest level, palms out. "Hey, I've got the complete ensemble. You're the one with headgear only."

Clint opened his mouth to reply but suddenly switched his attention to Steve. "Hey, Cap. You okay?"

Steve's nod was undermined by the full body shiver he gave and the way he choked on his attempts at deep breathing.

"Stark, what's wrong with him?" Clint turned to Tony, easing his own weight away from Steve and stepping back on his good leg.

"I don't know." Tony frowned, examining the captain. As he took in the tremors, the shallow breathing, sweaty complexion and obvious dizziness, he couldn't bite back another comment. "This might not be the time for it, but I just have to say...I told you so."

The glare Steve shot at him was weak, the bloodshot eyes more miserable than angry.

"See, this is why you should have listened to me from the start. Now you have no choice. I'm going to give you-"

"No, Tony. Your suit," Steve interrupted himself with a cough. "Your suit can't-"

A deep bass rumble from behind cut him off. The ground beneath Tony's feet vibrated, the water sloshing back and forth between the sides of the tunnel.

"What the..?" Clint limped a few steps back, staring down the tunnel through the eye slits in the borrowed helmet.

The gurgling thunder of approaching water was terrible to hear.

"Run!" Clint yelled.

There was no time. A torrential flood swept around the bend, crashing directly into the three heroes and sweeping them off their feet. White light spun madly as Tony was thrown haphazardly around the confined space. The current, such as it was, sucked at his body, pulling and pushing. It slammed him into the wall, his ribs taking the brunt of the collision, even through his suit. The light shuddered, FRIDAY calling out frantic warnings in his ear. A dark shape slid past him in the water. Clint.

With just a thought, Tony transformed the soles of his boots into rockets, lifting himself out of the water, despite FRIDAY's protests. He swooped after Clint's form, tracking the gleam of the helmet's eyes. The swirling stream carried the archer further away. Tony increased his speed until he overtook Clint, reaching down a hand and hauling the man from the water. There wasn't room enough in the tunnel, so Tony was forced to leave half Clint's body submerged. The strained groans coming from Clint attested to the pain the battering water was putting his legs through.

"FRIDAY, where's Cap?"

Silence from his AI.

"FRIDAY!"

"Sir, the amount of power you're currently using is draining the-"

"Cap, FRIDAY. Let's focus. Can you find Rogers?"

The water was an unrelenting surge, hurtling down the passageway.

"Sorry, boss. I am unable to locate Captain Rogers at this time."

"Can't or won't?" Tony snapped.

Clint wiggled beneath him. "There! Tony, he's over there!"

Somehow, Steve had found a crack in the wall's surface, some sort of imperfection in the concrete that he wedged his fingers into. And he was pressing himself flat against it, letting the water rage around him. It tugged at his body, trying to snatch him away from his perch, throwing stray jets up into his chest, his face. He was holding on but he was weakening. Tony could see that. He came closer, silently apologizing as Clint dragged through the water.

"Heads up, Cap!" Tony called, stretching out his other hand.

When Steve risked one hand to reach for Tony, he lost his grip and would have been swept away if Tony hadn't lunged for him and caught his wrist.

"Power levels at critical."

"FRIDAY, don't you dare-" Tony warned.

There was nowhere to go. Nothing but the rush of water coming from the tunnel behind them to the tunnel before them. Tony locked his hands more tightly around the fistful of Clint's uniform, around Steve's arm. He was disturbed to find the soldier as little more than dead weight in his grip.

"Boss, I can not maintain-"'

"You have to!"

A larger push of water smashed into Clint and Steve, tossing them forward. Taken off guard, Tony lurched forward too, struggling to regain his equilibrium.

"Stark!" Clint shouted.

"FRIDAY, how long can you give me?"

A series of calculations and graphs appeared on his HUD. "Seven or eight minutes, maybe ten maximum if I divert power from the reserves."

"And flight time?"

"I would highly recommend against such a course of action, given the circumstances. I can only guarantee sustained flight for ninety seconds, boss."

Mind racing, Tony asked, "How far are we from the end of the tunnel?"

"Earlier scans indicate the tunnel system extends for miles."

Tony sucked in a disappointed breath.

"However there is an access hatch eight hundred meters ahead."

The relief took Tony by surprise. "Why didn't you lead with that?"

"Why wasn't that your first question?"

Not deigning to give the AI a reply, Tony moved his focus to the two men dangling from his hands. "There's an access hatch up ahead."

That was all the warning he gave before jetting forward. Before long, the light of his arc reactor caught on the metal rungs that served as a ladder. He angled straight for it.

"Okay. The ride's over. Thank you for choosing Stark Airlines. We hope you enjoyed your flight."

Clint grunted and Tony couldn't make out what he said, though he doubted it was anything to be repeated in polite company. The archer wrapped his arms around the closest rung and once he was secure, Tony released him.

"Your turn, Cap."

Steve trembled in Tony's grip, his diaphragm heaving beneath the chest piece of his uniform. Still, he stubbornly followed Clint's example, hooking his hands around the metal bars. Tony hesitated behind him, reluctant to release him in case his hold wasn't as strong as it appeared. But Steve didn't fall.

"Boss, I'm shutting off all unnecessary functions and switching to auxiliary power."

"What? No. FRIDAY don't do that!" Tony's protests came too late. The AI was following its own programmed directives, conserving energy to afford him the longest use of the failing suit. "Great," he huffed, finding a place on the ladder as his thrusters shut off.

"Hey, I think we have a problem." Clint had pulled himself to the top and was struggling against the wheel crank that would open the hatch. "It won't budge."

"Shouldn't be a problem for me," Tony said. "Step aside, ladies."

With far more maneuvering than it should have taken, Tony and Clint managed to switch places, mindful of Steve draped over the middle rungs. The wheel showed the effects of age and little useage. Corrosion warped the edges of the hatch, spots of rust were dotted over the surface of the wheel. Underneath it as he was, trapped between the inclined wall beside him and Steve beneath him, the angle was awkward but Tony grabbed hold of either side of the wheel and pulled. The door didn't budge. The wheel wouldn't turn.

"Are you sure you're turning it the right way?" Clint called up at him.

"Lefty loosey, righty tighty," Tony growled. "Everyone knows that."

"I'm just saying."

Tony chose not to comment further, yanking harder on the metal. "What is wrong with this thing? It should be a piece of cake."

His AI answered his rhetorical mutterings. "The mechanism has been severely impaired by-"

"FRIDAY, if you're not actually going to be useful, you don't get to speak." Tony put more effort into it, twisting the wheel as hard as he could.

"Is the water supposed to be rising?"

At Clint's anxious question, Tony looked down to assess the water level and was dismayed to find the archer's observation was correct. The tunnel was filling quickly.

"Okay, we need to get this door open now," Tony said, though the statement wasn't directed at any particular person in the group. He doubled his efforts, with nothing to show for it. "What the hell?"

"Boss, I don't think you'll be able to open it."

"Thanks for the vote of confidence," Tony grumbled.

"The structure has been too badly damaged and the Mark Fifty-One doesn't currently possess the capabilities to force it open."

That froze Tony. "What?"

"The suit is nearly out of power. I have diverted what remains to sustaining the integrity of the breathing filters."

A moment passed, during which Tony struggled to process the new information, Clint called out another warning about how high the poisoned water was, and Steve slumped further against the ladder.

"We're screwed," Tony breathed.

A wave came uncomfortably close to the access hatch, spraying the heroes in a fine mist.

Clint yelped. "What's in this stuff?"

"What if you redirected power to the repulsors? Not a lot, just enough for a single blast to get this thing open." Tony's mind raced, seeking alternative solutions to the problem.

"Even if I could, boss, it's highly likely the fumes would ignite."

"So we're dead either way?" Tony said.

"I'm afraid so."

A hand, red and blistered, curled over Tony's shoulder. "Let me."

Tony turned to find that Steve had hauled himself up the ladder, closer to the hatch, despite how sick he was. There was no denying it now. The lack of color in his skin, puffy irritated eyes, thick drops of sweat rolling down from his temples, how his diaphragm heaved with every shallow breath were all obvious signs of just how bad he was being affected.

"Cap, no. You're in no condition," Tony started.

"I can do it," Steve insisted, expression fierce.

Tony glanced down to Clint, though it was impossible to determine what the archer was thinking when the mask covered his face.

"Whatever we're going to do, we need to do it fast," was all Clint said, voice tight as he dragged himself higher, hoping to keep his broken leg out of the flood.

"We don't even know what's up there. What if they're waiting for us and we come out into an ambush? What if the leak spread through the entire factory? What if-"

"Tony," Steve interrupted. "Stop. We'll just have to take our chances. If we stay here, we die." An intense coughing fit stole away the rest of his words.

Reluctantly, Tony shifted around and down as Steve climbed higher. After positioning himself under the door, Steve grasped the decaying metal wheel in both hands and twisted. Tony and Clint watched on. Harsh panting rebounded off the tunnel, Steve's labored breathing difficult to listen to. He sagged after his first attempt and Tony's stomach clenched.

"You good, Rogers?"

Instead of answering, Steve rallied himself and went at the wheel again.

"Uh, Stark. A little help?"

Tony turned to find Clint scrambling to get higher on the ladder as the water swallowed the bottom rungs. Cursing under his breath, Tony grabbed Clint's forearm and pulled him closer, climbing himself until they were equal with Steve's waist.

"I don't want to rush you or anything, but do you think you could hurry and get us out of here?" Tony looked up at Steve.

The soldier's lips were peeled away from his gums, teeth clenched with immense pressure, and the veins in his forehead bulged as he strained against the rusted mechanism. Worry crawled around in Tony's brain, not simply because the thought of drowning was disconcerting, but because he was witnessing Steve struggle. In all the years he'd known Rogers, he had never seen Steve in any condition other than perfection. The serum was indeed a miracle and a wonder, somehow providing the man with the epitome of strength and health. So to see him ill and weak and fighting against the door when he should he been able to open it like it was nothing was an entirely unnerving shock.

"Come on, Cap. Come on," Clint muttered beside him, glowing eyes of his helmet fixed on Steve.

"Boss, there's a massive influx of water headed this way."

"What?" Tony's gaze flicked over to the warning on the bottom corner of his display.

"According to my calculations, Captain Rogers must open the hatch within the next twenty seconds."

"Cap, we've got incoming. If we're going to make it out of here, you need to get that thing open right now!"

"What do you think he's doing?" Clint said hotly.

"No, I mean like right now, right now. FRIDAY did the calculations. If that's not open in the next fifteen seconds, we're all going to die," Tony said.

Steve dropped his chin to his chest, hacking deeply and roughly into his shoulder.

"We're not going to make it," Tony whispered in growing horror.

"Don't say that. He's got this," Clint snapped.

The water slapped in angry waves at their boots, devouring several more rungs. Tony stared at it with wide eyes. Under better circumstances, he wouldn't have been afraid. At any other time, his suit would protect him, sealing tight to keep the water out. But he had given some of his nanobots to Clint to provide the other man with a filtration system. And the earlier fight in the factory had heavily damaged his power systems, with the time in the tunnel only depleting the already limited power. If the water filled the tunnel, they were all going to die.

Steve straightened and tightened his grip on the wheel. Then he gave a hoarse cry and threw all his weight behind his next attempt. He wrenched his torso to the side as he pulled and the wheel shifted with a rebellious shriek of metal. Tony nearly whooped in relief. But the hatch wasn't open yet. The muscles in Steve's body trembled, even as he yanked on the wheel again, spinning it open a hard-fought inch at a time. Light spilled through the widening crack and Tony squinted against it. Steve gave a final heave and they were free.

"Clint," Steve panted, curling one arm around the top rung. "Give me your hand."

Without hesitation, Clint reached for Steve and the soldier gripped him hard, hauling him up the ladder and lifting him out of the tunnel. Once Clint was safe on the other side, Steve turned to Tony.

"I'm a big boy. I can climb a ladder by myself," Tony ribbed, moving past Steve.

He joined Clint in what turned out to be some sort of hallway in what Tony assumed was the basement of the chemical plant they'd been sent to investigate. "Well, would you look at that. We made it."

"Told you he'd get us out," Clint said, sprawled back on his elbows, his legs outstretched in front of him.

"You're right. I never should have doubted our fearless leader. Captain Muscles saves the day again." Tony turned around, expecting to meet Steve's eyeroll.

Steve wasn't there.

"Cap?" Clint sat up straighter.

"Where…" Tony knelt to peer back into the hole. "Steve!"

Dragging himself closer, Clint craned his neck. "What? Where is he?"

Contaminated water rolled by the opening, frothy now with the increased levels and higher waves. Tony's gaze darted around frantically, hoping for a glimpse of their missing teammate. If Steve had gotten washed away, if he was gone…

"I see him!" Clint's palm slapped clumsily at Tony's bicep. "He's still on the ladder."

Tony leaned over further. "Where?"

"He's down near the bottom. I don't think he's moving," Clint relayed, tone pitched with fear. "He might be trapped."

Without taking the proper time to consider all the pros and cons of the decision, Tony peeled himself out of his suit. "Give me everything you have left, FRIDAY." The helmet melted away from Clint's head and joined with the rest of the suit as it reformed itself on the edge of the hatch.

"Go get him."

The arc reactor sputtered in its casing twice before following Tony's order and diving directly into the tunnel. Tony waited breathlessly for the armor to reappear, Clint just as tense beside him.

"How long is this supposed to take?" Tony said, in spite of being aware that scarcely ten seconds had passed.

With a spray of liquid, the Mark Fifty-One burst from the access hatch.

"Steve?" Clint called. "Did it work? Tony, did we get him?"

The suit laid itself down on the floor beside Clint. Tony exchanged a confused glace with him. Then the nanotechnology shrunk in on itself, collecting back into the arc reactor to reveal Steve's body underneath.

"Steve," Clint exhaled, curling his fingers around the collar of Steve's uniform. "Steve, wake up. Come on, damn it. Open your eyes."

There was a disturbing blue tinge to Steve's lips, and his eyelids looked bruised. Blisters were spread across his exposed skin, puffy and angry looking.

"Is he…" Tony hesitated.

A harsh nod from Clint was his reply, though Tony noticed the archer did move his hand to jab a couple of fingers into the pulse point on Steve's neck. Uncertain of his role, Tony bent to collect the arc reactor. When he touched it, the power source sparked, sending a mild jolt rippling through both Tony and Steve. Tony immediately jerked back, cradling his tingling hand to his chest. Steve's body spasmed and his eyes flew open. He gasped, rolling painfully to his side and coughing miserably, a thin trickle of liquid dribbling out of his mouth.

"You're okay," Clint murmured. "You're okay. Easy now. It's all good. You're fine."

After hacking wetly until he didn't have enough air for it, Steve moaned. Clint helped him shift onto his back, where he could stare up at the ceiling.

Tony winced. "You look awful."

Steve barely acknowledged the comment, lifting his eyebrows slightly before letting his eyes slip shut again, stifling a cough.

"Stark, please tell me you have a way to call for backup because, between my leg and Cap's chemical exposure, there is no way we're getting out of here on our own," Clint said.

Before Tony had the chance to answer, Steve started pushing himself up with a groan. "I'll get us out of here."

"Whoa, whoa, hey. Calm down. The only thing you need to do is take it easy." Clint grabbed his shoulders, pushing him back down.

"I can do it," Steve grunted, ignoring Clint's words.

Clint put more pressure on his shoulders. "We know. But you've done enough already."

It was undeniable evidence of how sick Steve was that he let Clint stop him.

"Yeah. I'm sure I can figure something out," Tony said. "Or maybe I can find some stuff around here we can use. Like a walker for you, bird-man. And I could probably find a dolly for Cap. Just strap him in and wheel him around. That would work, right?" Steve rolled his eyes and Tony smirked.

"By the way, guys," Clint interrupted. "Don't take this the wrong way, but missions never went this far south when I was running them solo for SHIELD."

"Well, now you're an Avenger and you get to have all this fun." Tony gestured to encompass the factory, the tunnel they'd nearly drowned in, Clint's broken leg and Steve's near death experience.

Clint shook his head, a wry smile stealing over his face. "You're right. What was I thinking? Almost dying: that's just another day at the office."


End file.
